btrfs subvolume create /swap
btrfs filesystem mkswapfile --size 16g --uuid clear /swap/swapfile
swapon /swap/swapfile

echo '/swap/swapfile none swap defaults 0 0' >> /etc/fstab
echo 'vm.swappiness = 200' >> /etc/sysctl.d/99-sysctl.conf
sysctl --system